Dynamo-electric machine



H. H. WAIT.

DYNAMO ELECTRIC MACHINE.

HIP

2 SHEETS-SHEET 1.

H. H. WAIT. DYNAMO ELECTRIC MACHINE.

2 SHEETS-SHEET 2.

PATENT OFFICE.

HENRY H. WAIT, OF CHICAGO, ILLINOIS.

DYNAMIC-ELECTRIC MACHINE.

Specification of Letters Patent.

Patented Dec. 13, 1921.

Application filed August 23, 1917. Serial No. 187,782.

To all whomz't may concern:

Be it known that I, HENRY H. WAIT, a citizen of the United States, residing at Chicago, in the county of Cook and'State of Illinois, have invented a certain new and useful Improvement in Dynamo Electric Machines, of which the following is a full, clear, concise, and exact description.

My invention relates to dynamo electric machinesandhas for one of its objects vthe simplification of means for lessening the noise occasioned by rotating armatures. to

My invention also has for its object an improvement in the ventilating arrangement of the armature to improve the circulation of armature cooling air. The preferred way of achieving the second object of my invention also lessens the noise produced by the tangs, but I do not limit myself to this added advantage.

In carrying out the first object of- 'my invention I afford an air inlet adjacent the armature tangs from which the air flows to the tangs and ultimately along the tangs in outward directions so that the air and tangs are rotating at substantially the same velocity at the outer ends of the tangs where the cooling air leaves the armature and where the greatest noise is likely to occur.-

The air enters at places where the speed is relatively low to reduce the noise at the places of entry, velocitylbeingincreasingly imparted to the outwardlymoving ail-until it is substantially that of the tangs where the air leaves them. 7 4 I In carrying out the second object of my invention I subdivide the armature into zones with ventilating spaces between, through which armature cooling" air finds its way. Air distributing channels are provided with air distributing portions near the axis of the armature for efi'ecting circulation of cooling air through said spaces. The end of each channel adjacent the commutator is sufliciently closed to prevent the commutator tangs from acting as a centrifugal fan to suck a material quantity of the air directly through the channels and divert it away from the ventilating spaces. In preventing this action of the commutator tangs upon-the air flowing. through said channels, I eliminate the noise that the actron of the tangs upon this air would occa- SlOIl.

I will explain my invention more fully by reference to the accompanying drawings showing the preferred embodiments thereof and in which Figure 1 is a longitudinal view, partially in section and partially in elevation of a dynamo electric machine 5onst'ructed in accordance with the invention; Fig. 2 is a view on line 22 of Fig. 1; Fig. 3is a detail view, somewhat diagrammatic or the structure illustrated in Fig. l and F1g. 4 is a, detail view in transvcrsesection.

Like parts are indicated by similar characters of reference throughout in both figures.

The dynamo electric machine illustrated has a field portion not shown which is inclusive of a field ring, radial pole pieces car ried by and projecting inwardly from the ring, and field coils. The armature 4 is carried upon 'a shaft 5 which turns within bearings 6 that are supported by standards 7' upon a base 8. The dynamo electric machineshownis one which operates at a high rate of speed, on whichaccount its commutator 9 is surrounded by annular steel bands 10 (suitably insulated from the commute tor) and serving to prevent the commutator bars from being dislodged or misshapen through the action of centrifugal force. The commutator brushes ll .(of which only onell is illustrated in Fig. 2) are disposed upon studs 12 which are anchored at their inner ends to an annular carrier 13 and at their outer ends to an annular carrier- 14. These annular carriers 13 and 14* are do sirably respectively disposed in the planes of rotation of the inner and outer steel bands 10. The two outer bands 10 and the adjacent bearing 6, together with its supporting standard 7, prevent mere endwise displacement or removal of the carriers 13 and 14 and the brushes 11 carried thereby, on which account I form the carriers in sections that meet on diametrical lines of the carriers. When the carriers are thus formed in split sections, providing they are suitably mounted, they may readily be Withdrawn from the machine by a movement thereoi a ing 16 may be made of iron, while the inner in the plane of rotation of the commutator, a result which may be eifected without disturbing individual adjustments of the commutator brushes 11. The brush structure that includes the carriers 13 and -14, the

studs 12 and the brushes 11 upon said studs, is mounted to rotate upon an axis coincldent with the axis of theshaft 5. ,The mounting is preferably double, there being a mounting 15 for and concentric with the carrier 18,an d a mounting 16 for and concentrlowith the carrier 14. The carrier1l5is mounted upon: the base 8 rather than upon any portion of the dynamo electric machine itself. By dividing the mounting structure intotwo separate mountings 15 and 16 the outer mountmounting may be made of non-magnetic ma terial for the purpose which has been stated.

The mountings 15 and 16 are desirably-segmental, the, engagement thereofjwith the J rings 13 and 14 being limited to areal-poradjustingv the position of the brushes with 4: ing velocity to the respect tothe axis of commutation.

Whether the other surfaces'of the carrier rings are smooth or not, the carrier ring 13 is practically smooth on the sidetoward the commutator tangs 17. This carrier ring, in combination with the rings and supporting drum of the armature, forms a chamber resembling the casing and diifuser of a centrifugal fan. 7 The ring-13,}being located close to the tangs 17,'prevents' these tangs from cutting through the stationary surrounding air. The air enters'the space-be tween ring 13'and the armature through the slight annular space 18 that" intervenes between the ring 13 and the-band 10 that is in theplane of and surrounded by ring 13. The portions of the commutator tangs where the air inlet is located run at a relatively lower speed. The tangs impart an increasalong'the tangs, the velocity of'thetangs and air being substantially'equal atthepd' riphery of the body of tangs, where "the airleaves the armature, whereby noiseis eliminated or materially reduced at thislocality where there is usually loud noise.

y this arrangement, I have reduced the windage loss of a machine two or three kilowatts, an increase of two or three-per cent 1n efficlency 1n machines of thekind illusi has been 'furtherreduced by m' trated, a result which is obtained without inclosing the machine and preferably bygthe use ofa ring that performs the additional function of carrying commutator studs. proved ventilating construction-i The rm ture is-provided with longitudinal ventilat mg channels 19 located near the axis of an passing outwardly-f rotation and in communication with transverse Ventilating spaces 20. The ends of the channels 19 adjacent the commutator are,

completely or sufficiently. closed by plugs 21 to prevent the commutator tangs, that act as a centrifugal fan and very forcefully at high speed, from sucking the bulk of the alrpassing through said channels directly .out of the channels themselves and shunting the cooling air that would otherwise be free for passage through the ventilating spaces 20;; The spacers 22 in'the spaces 20 form fans that furnish just enough air to cool the core, eta, excess of air being prevented from' getting to the commutator tangs either through the armature or at the ends; Enough 'air'is thus blown without any useless excess that would waste power ring and nearer the axis'of the armature than the periphery ofthe body of tangs; and a commutator brush structure of which said ring forms a part. I

'2.;A dynamo electric machine, including its armature and commutator, said armature having transverseventilating spaces and longitudinal air channels in communication with said ventilating spaces; commutator tangs' at the inner end of the commutator; and plugs-entering-the inner ends of said longitudinalair channels. 7 '3'. In a dynamo Lelectricmachine, the combination with an armature provided with windings; of a commutator provided with tangs connected to said windings; a shield ringaxially adjacent said tangs on the outside andex'tending radially beyond them; and afsecond ring axially adjacent said tangs on the inside and extending radially beyond them. t V V 4; In a dynamo electric machine, the com- 1 'bination' with an armature provided with windings, of a commutator provided with tangs connected-to said windings; a shield ring axially adjacent said tangs on the outside and extending radially beyond'them; and a second ring axially adjacent. said tangs on theinside and extending radially beyond them, said rings forming a diffusion passage outside the tips of said tangs.

5; a dynamoelectric machine, the combination With a laminated armature core;

dynamo electric machine, including of windings on said core; a commutator; passages and said commutator ventilating tangs connecting said commutator and Said passages.

windings; there being ventilating passages In witness whereof, I hereunto subscribe 10 in said armature core and other ventilating my name this 22nd da of August A. D., passages adjacent said commutator tangs; 1917.

and separate means for adjusting the area of communication between said core ventilating HENRY H. WAIT. 

